Rewrite page(2) references to page(3).
Add description of new libmach.
diff --git a/man/man3/exec.3 b/man/man3/exec.3
index 5ce9583..bf10cb5 100644
--- a/man/man3/exec.3
+++ b/man/man3/exec.3
@@ -34,7 +34,7 @@
to be executed; it must not be a directory, and the permissions
must allow the current user to execute it
(see
-.IR stat (2)).
+.IR stat (3)).
It should also be a valid binary image, as defined in the
.IR a.out (6)
for the current machine architecture,
@@ -103,7 +103,7 @@
.B OCEXEC
OR'd
into the open mode; see
-.IR open (2));
+.IR open (3));
and the working directory and environment
(see
.IR env (3))
@@ -112,7 +112,7 @@
.I exec'ed
process has no notification handler
(see
-.IR notify (2)).
+.IR notify (3)).
.PP
When the new program begins, the global cell
.B _clock
@@ -147,8 +147,8 @@
.B /sys/src/libc/port/execl.c
.SH SEE ALSO
.IR prof (1),
-.IR intro (2),
-.IR stat (2)
+.IR intro (3),
+.IR stat (3)
.SH DIAGNOSTICS
If these functions fail, they return and set
.IR errstr .
